A standard hand shower such as described in German patent document 2,827,847 filed on 24 Jun. 1978 by H. J. Schmidt has a short tubular male element that is screwed onto the lower end of the hand shower and that can be fitted in a female snap coupling that in turn is screwed onto the outer end of the feed hose. Buttons on the female part of the coupling can be pressed to release the male part of the device and allow the hand shower to be switched for one offering a different spray pattern or other features.
The disadvantage of this arrangement is that a rather bulky assembly is interposed between the rear end of the hand shower and the outer end of the hose. This coupling adds to the size of the assembly. In addition the connection thread on the hand shower necessitates a connecting element of the coupling which is circular in section so that the location at which it is screwed tight is independent of the angular position. Finally it is not uncommon for hand showers to vary widely in dimensions, so that the coupling supplier must stock a large number of the couplings in order to match the shape and size of the various couplings.